xen/blkfront: don't put bdev right after getting it

We should hang onto bdev until we're done with it.

Signed-off-by: Andrew Jones <drjones@redhat.com>
[v1: Fixed up git commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 619868d9..537cb72 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1409,7 +1409,6 @@
 	mutex_lock(&blkfront_mutex);
 
 	bdev = bdget_disk(disk, 0);
-	bdput(bdev);
 
 	if (bdev->bd_openers)
 		goto out;
@@ -1440,6 +1439,7 @@
 	}
 
 out:
+	bdput(bdev);
 	mutex_unlock(&blkfront_mutex);
 	return 0;
 }